If we use dannic's rationale: We don't know what any couple's relationship is. So, if a husband hits his wife, let's say it's ok. I mean after all--we don't know. She could have done or said something to "provoke" him.
Really people. Wrong is wrong. There is no rationale to excuse some things.

__________________
Mental that one, I'm telling you. ---Ron Weasley, "Harry Potter and the Chamber of Secrets"